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Full text of "The Morphology And Evolution Of The Apes And Man"

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region.    The outer column or ilio-costalis (I-C.C.) arose along with the subjacent longissimus from the iliac crest between the highest point and the  posterior  superior spine, and it derives fibres from the covering posterior lamella of the lumbo-dorsal fascia.    It gives two slips to the lower borders of the twelfth and thirteenth ribs, of which the former is  the  larger.     It receives a large number of muscular slips from the outer surfaces of all the ribs, the size of the latter diminishing from below upwards.    Many of the small muscular slips  are continuous with the slips given off from the longissimus. Erom  the outer border  of the  muscle,  long,  slender tendons run to the lower borders of the angles of the first nine ribs.    The longissimus (Lo.C) arises from the crest of the ilium from the highest point to the posterior superior spine, the posterior sacro-iliac ligament, the back of the sacrum, all sacral and lumbar vertebral spines and the spines of the twelfth and thirteenth dorsal vertebrae. It  gives  slips to  the lower borders  of   ribs 4 to  13 between their angles and the transverse processes.    The attachments to the first three ribs come from the combined longissimus and ilio-costalis.    The combined outer and middle columns divide into slips which are attached to the posterior tubercles of the transverse processes of the third, fourth and fifth cervical vertebrae along with the levator angulse scapulae.    The third cervical vertebra thus receives splenius cervicis, levator  anguli scapulae and longissimus.    The part of longissimus attached to these processes corresponds to longissimus cervicis in Man, but is not so extensive.    The spijialis dorsi (S.C.) is a narrow muscle arising from the longissimus dorsi and the eleventh and twelfth dorsal spines.   It is inserted